[tldistro] texlive2021 pretest images & rfp

[Karl Berry]

    Mostly man pages

Sorry, I missed two of them before. No comments on dv2dt, applied as is.

For gftodvi, I resist the idea that we should have two spaces after
periods; few other TeX man pages do that. I made it consistent in the
other direction, with one space.

However, I would prefer not to worry about this; I'm sure plenty of
inconsistencies remain in this regard, and they should make no
difference to anyone, so I hope we can just let it slide.

It would be a much more useful way to spend time to actually improve the
content of the web pages instead of these trivial formatting
things. They could all use enhancement and updating. Unfortunately such
things can't be automated. --best, karl.